Cycloidal drives are commonly used as speed-reducer mechanisms. A typical cycloidal drive includes an input shaft having an eccentric end connected to a cycloidal disk via an eccentrically mounted bearing. The disk includes a plurality of lobes that intermesh with ring pins circumferentially surrounding the disk. The ring pins are typically stationary with the housing of the speed reducer. An output shaft includes an array of circumferentially arranged rollers that are received within holes defined in the cycloidal disk. The input shaft drives the disk in an eccentric, cycloidal motion. Motion is transferred from the disk to the output shaft via the plurality of rollers. The eccentric, cycloidal motion of the disk reduces the speed between the input shaft and the output shaft according to the number of lobes, holes, pins, and rollers. The difference between the number of rollers and the number of lobes is usually one, and the number of lobes usually matches the number of pins.